class Test1():
    def __init__(self):
        self.t1="我是父类"

    def f(self):
        return "爸爸"

class Test2():
    def __init__(self):
        self.t2="我是子类"

    def f(self,object):
        print(object.f)

a=Test1()
b=Test2()
b.f(a)

def main(object):
    print(object.f())

    return "123"

print(main(a))